Update Silex Plugin to work with master

Also change lite_cqrs.event_message_bus to event_message bus. This is
done because it is a main entry point for LiteCQRS just like the
command_bus is.
fix typo
Small README.md fixes
Merge pull request #44 from aderuwe/patch-5

Small README.md fixes
Merge pull request #38 from henrikbjorn/silex-update

Update Silex Plugin to work with master
[GH-43] Handle serialization of LiteCQRS classes with JMS Serializer by magic trickery, avoiding to use the annotation and failing for some people.
Remove AggregateRootHandler for JMS Serializer, which broke stuff.
Add travis build icon
Remove ENV in .traivs.yml
Include mongo.so to run LiteCQRS tests.
Fix bug in TableEventStore